What is "danger space"

n. 1 (context military English) The areas between a weapon and its target in which the trajectory is not greater than the typical height of a human (about 1.8 meters) 2 (context military English) The area or space around the target of a missile in which it has a probability of landing or exploding 3 (context medicine English) A region of the neck bounded by the skull base, alar fascia and prevertebral fascia, from which an infection can spread directly to the thorax.

The danger space is a region of the neck.